I have a male Boxer, he will be 1 year old September 29. This morning he was acting like he could hardly move and looked really sad. I took him to the vet this morning, he has a temp of 104 but the vet didn't know what is wrong with him. He got a shot and has been laying on the bed for a couple of hours now and doesn't get up. He is normally very active and playful. Please help me to make him better!